Diskospondylitis in Dogs

I have a really big, 2 year-old, mixed breed dog (90 pounds) who suddenly started having severe back pain. He could barely stand up and could not walk very far. My veterinarian says that he has diskospondylitis. I am confused about this infection and how he got sick, although he did get into a fight with another dog a while ago.

Diskospondylitis involves infection and inflammation of the disks between the vertebrae in the spine. The disks act as shock absorbers in the spine, and help to facilitate spinal movement. The infection may be bacterial or fungal. Diskospondylitis most commonly occurs in large and giant breed dogs. German Shepherd dogs and Great Danes seem to be over-represented in the population of affected dogs.

"Most dogs experience a sudden onset of signs and symptoms."

While the mean age of dogs with diskospondylitis is 4–5 years of age, the range of ages is quite wide, from 5 months to 12 years of age. Males are much more commonly affected by a ratio of 2:1. Most dogs experience a sudden onset of signs and symptoms. The most common first clinical signs of diskospondylitis are difficulty getting up from a down position, reluctance to jump, and an abnormal, unstable gait, including lameness.

Are there other signs or symptoms associated with diskospondylitis?

Dogs with diskospondylitis often lose their appetite and lose weight. They may develop wounds or draining tracts at the level of the affected intervertebral disks. While any disk along the spine may become infected, the lower lumbar area is most often involved. The majority of these dogs have back pain in one or more spots, and they may develop rear leg weakness or even paralysis, especially if the infection becomes chronic or is left untreated. Finally, about 30% of dogs with diskospondylitis will have a fever.

What causes diskospondylitis?

Diskospondylitis can be caused by either a bacterial or fungal infection. The most commonly involved bacteria include Staphylococcus intermedius, Streptococcus, Brucella canis, and E. coli, but almost any bacteria can be causative. As for fungal infections, Aspergillus, Paecilomyces, Scedosporium apiospermum, and Coccidioides immitis are most commonly associated. The inoculation of the tissues with an infectious organism that can result in diskospondylitis may come from a migrating grass awn or a bite wound.

Other risk factors for diskospondylitis include surgery, periodontal disease (infection in the gums around the teeth), skin infection, infection of the lining of the heart (endocarditis), and a deficiency of the immune system.

How will my dog be treated for diskospondylitis?

Most dogs with diskospondylitis are treated as outpatients rather than in the hospital. Pain management is a very important part of treatment. If the dog loses the ability to walk, it is important to keep her clean and dry, allowing her to be on a well-padded surface, and turning her regularly to help prevent pressure sores.

"Activity should be restricted in order to
maximize comfort."

Activity shoudl be restricled in order to maximize comfort. Occasionally surgery is required to remove the infected tissue or to remove pressure on the spinal cord.

The selection of an appropriate antibiotic to treat diskospondylitis will depend on the results of blood cultures, antibiotic sensitivity testing, and a test for Brucella canis. If these tests are negative, then the veterinarian will treat presumptively with a cephalosporin antibiotic for 8–12 weeks. Dogs who do not respond to their initial treatment will be treated with an antibiotic from a different family.

What about follow-up during treatment?

Most dogs being treated for diskospondylitis are re-evaluated within 5 to 7 days to measure their response to the antibiotics. If there is no (or minimal) improvement in pain, fever, or appetite, then the treatment plan must be reassessed. A different antibiotic may be chosen, or the area may be aspirated with a needle and syringe to remove infected debris. If the dog is improving, then ongoing re-evaluation every 4 weeks will be both by clinical examination and follow-up x-rays to assess healing.

What are some possible complications of diskospondylitis?

The spinal cord of dogs with diskospondylitis may become compressed secondary to scar tissue or excess bone in the vertebrae that may form during healing. Vertebrae in the spine may fracture or dislocate due to the tissue damage from the infection. The dog may experience meningitis or meningomyelitis—inflammation of the spinal cord and/or the membranes surrounding the cord. It is also possible for an abscess to form in the epidural space surrounding the spinal cord.

What can I expect for my dog as he recovers from this disease?

It is critically important to deliver the prescribed antibiotics for the entire time for which they have been prescribed, which may be as long as 3 months. If antibiotic therapy is withdrawn prematurely, then a recurrence of diskospondylitis is likely. Some dogs may need to receive antibiotics for a year or longer. The long-term outcome depends upon the infectious organism and the amount of damage done to the spinal cord.

Dogs who have no nervous system damage, or who only have mild clinical signs, will typically respond to therapy within one week’s time. On the other hand, those dogs experiencing significant weakness or paralysis have a guarded prognosis, and may not ever recover their full function. Because it is difficult to predict the restoration of function early in the course of therapy, treatment is advised, despite that uncertainty. Should clinical signs recur or progress, it is important to contact your veterinarian right away.